Rh-catalyzed asymmetric transfer hydrogenation. This transformation allowed the reduction of both the C═C and C═O bonds and the formation of two stereocenters in high yields with excellent levels of diastereo- and enantioselectivities (up to >99:1 dr, up to >99% ee) in a single step through a dynamic kinetic resolution process using a low catalyst loading and HCO2H/DABCO as the hydrogen source.
通过Rh催化的不对称转移氢化反应,可以直接从(E)-3-亚苄基-苯并二氢吡喃酮中获得对映异构体富集的顺式-3-苄基-苯并二氢苯并二氢苯并二氢吡喃酚。这种转变可以降低C═C和C═O键,并以高收率形成两个立构中心,且非对映和对映选择性极好(高达> 99:1 dr,高达> 99%ee)。通过动态动力学拆分过程的一个步骤,即使用低催化剂负载量和HCO 2 H / DABCO作为氢源。
Ketone–Olefin Coupling of Aliphatic and Aromatic Carbonyls Catalyzed by Excited-State Acridine Radicals
作者:Nicholas J. Venditto、Yiyang S. Liang、Roukaya K. El Mokadem、David A. Nicewicz
DOI:10.1021/jacs.2c04822
日期:2022.7.6
easily reducible aromaticcarbonyl compounds. Herein, we describe a mild, metal-free ketone–olefin coupling reaction using an excited-state acridine radical super reductant as a photoredox catalyst. We demonstrate both intramolecular and intermolecular ketone–olefin couplings of aliphatic and aromaticketones and aldehydes. Mechanistic evidence is also presented supporting an “olefin first” ketone–olefin
Pfeiffer et al., Justus Liebigs Annalen der Chemie, 1949, vol. 564, p. 208,219
作者:Pfeiffer et al.
DOI:——
日期:——
Pfeiffer et al., Justus Liebigs Annalen der Chemie, 1949, vol. 564, p. 108,215
作者:Pfeiffer et al.
DOI:——
日期:——
Photoredox-Catalyzed Ketyl–Olefin Coupling for the Synthesis of Substituted Chromanols
作者:Eleonora Fava、Masaki Nakajima、Anh L. P. Nguyen、Magnus Rueping
DOI:10.1021/acs.joc.6b01006
日期:2016.8.19
A visible light photoredox-catalyzed aldehyde olefin cyclization is reported. The method represents a formal hydroacylation of alkenes and alkynes and provides chromanol derivatives in good yields. The protocol takes advantage of the double role played by trialkylamines (NR3) which act as (i) electron donors for reducing the catalyst and (ii) proton donors to activate the substrate via a proton-coupled
报道了可见光光氧化还原催化的醛烯烃环化。该方法代表烯烃和炔烃的正式加氢酰化,并以良好的收率提供色原醇衍生物。该协议利用了三烷基胺 (NR 3 ) 所起的双重作用,它们充当 (i) 电子供体以减少催化剂和 (ii) 质子供体通过质子耦合电子转移激活基板。